A new method for the fabrication of monodispersed Cu nanoparticles on electrode surface was explored, and a novel electrochemical sensor for the sensitive detection of hydrogen peroxide (H2O2) was constructed by assembling copper nanoparticles (Cu-NPs) on the precursor film poly-p-aminobenzene sulfonic acid (poly-ABSA) electropolymerized on glassy carbon electrode (GCE). The assembly process consisted of two steps: the ion-exchange and coordination of Cu2+ with the sulfonic groups contained in poly-ABSA film, and the subsequent in-situ reduction of Cu2+ ions to Cu-NPs by electrochemical method. The results of scanning electron microscopy (SEM) showed that Cu-NPs were highly monodispersed in whole poly-ABSA, which was strongly attached to the electrode surface. The modified electrode Cu-NPs/poly-ABSA/GCE was also characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and exhibited excellent electrocatalytic activity toward the reduction of H2O2 with high stability. Amperometry was used for the determination of H2O2 at a more positive potential of -0.2 V versus Ag/AgCl in pH 7.0 phosphate buffer solution, with a linear range from 0.2 mu M to 2.32 mM and a detection limit of 0.1 mu M. The Cu-NPs/poly-ABSA/GCE allowed sensitive, stable and fast amperometric sensing of H2O2, and this was promising for the development of nonenzymatic sensors. The analysis of medical disinfection solution real samples was performed using the proposed method, and the obtained results were satisfactory. (C) 2015 Elsevier B.V. All rights reserved.